JP5192536B2 - Cu-Ni-Si based copper alloy sheet excellent in deep drawing workability and fatigue resistance and method for producing the same - Google Patents

Description

  The present invention relates to a Cu-Ni-Si-based copper alloy excellent in deep drawing workability and fatigue resistance, and in particular, as a material for various electronic components, used in a predetermined shape for a long time in a high temperature and high vibration environment. The present invention relates to a Cu—Ni—Si based copper alloy that can withstand heat resistance and a method for producing the same.

As electronic devices have become lighter and thinner in recent years, relays, terminals, connectors, etc. are also becoming smaller and thinner, and the copper alloy materials used for them are required to have high strength and bending workability. .
Accordingly, the demand for precipitation-strengthened copper alloys such as corson (Cu—Ni—Si) alloys, beryllium copper and titanium copper is increasing in place of conventional solid solution strengthened copper alloys such as phosphor bronze and brass.
Among them, the Corson alloy is an alloy in which the solid solubility limit of the nickel silicide compound with respect to copper changes remarkably with temperature, and is a kind of precipitation hardening type alloy that hardens by quenching and tempering. Good high-temperature strength, excellent balance between strength and electrical conductivity, widely used in various springs for electric conduction and electric wires for high tensile strength, and recently used in electronic parts such as relays, terminals, connectors, etc. Is growing.
Generally, strength and bending workability are contradictory properties, and in Corson alloys, it has been studied conventionally to improve bending workability while maintaining high strength, adjusting the manufacturing process, crystal grain size, There have been widespread efforts to improve bending workability by controlling the number, shape, and texture of precipitates individually or mutually.
In addition, in order to use Corson alloy in various electronic parts in a predetermined shape for a long time in a harsh environment, fatigue characteristics, bending workability, and ease of processing to make a predetermined shape, particularly excellent Deep drawing workability is beginning to be required.

Patent Document 1 contains 1.0 to 4.0% by mass of Ni and 1/6 to 1/4 concentration of Si, and the frequency of twin boundaries (Σ3 boundary) in all grain boundaries. Has disclosed a Cu—Ni—Si based alloy for electronic parts having a good balance between strength and bending workability of 15 to 60%.
In Patent Document 2, each difference between the tensile strength in the rolling direction, the tensile strength in the direction of 45 ° with respect to the rolling direction, and the tensile strength in the direction of 90 ° with respect to the rolling direction. Is a copper-based precipitation type alloy sheet for contact material having a maximum value of 100 MPa or less, contains 2 to 4 mass% Ni and 0.4 to 1 mass% Si, and further contains Mg, Sn, Zn, Cr if necessary. A copper-based precipitation type alloy sheet is disclosed in which the balance containing at least one selected from the group is made of copper and inevitable impurities. The copper-based precipitation type alloy sheet for contact material is a multi-function switch that is manufactured by subjecting a solution-treated copper alloy sheet to aging heat treatment, and then subjecting it to cold rolling with a rolling rate of 30% or less. Improve the operability.
Patent Document 3 discloses a Corson (Cu—N—Si) copper alloy plate having a yield strength of 700 N / mm ² or more, an electrical conductivity of 35% IACS or more, and excellent bending workability. This copper alloy plate has Ni: 2.5% (mass%, the same shall apply hereinafter) and less than 6.0%, and Si: 0.5% and less than 1.5%. In the range of 4 to 5, Sn: 0.01% or more and less than 4%, the balance is made of Cu and inevitable impurities, the average crystal grain size is 10 μm or less, and measurement by SEM-EBSP method As a result, after having a texture where the ratio of Cube orientation {001} <100> is 50% or more and obtaining a solution recrystallized structure by continuous annealing, cold rolling with a working rate of 20% or less and 400 to 600 It is manufactured by performing an aging treatment at 1 ° C. for 1 to 8 hours, followed by a short annealing at 400 to 550 ° C. for 30 seconds or less after the final cold rolling at a processing rate of 1 to 20%.
Patent Document 4 discloses a copper alloy sheet material suitable for electric / electronic parts that has significantly improved bending workability and fatigue characteristics while maintaining high conductivity and strength. By subjecting the cold rolled material to repeated bending with a tension leveler, the average hardness Hs (HV) at the 1/8 position in the plate thickness direction and the average hardness Hc (HV) at the 1/2 position in the plate thickness direction are (Hs− Hc) / Hc × 100 ≦ −5 A copper alloy sheet in which both surface layer portions are softer than the center portion. The alloy composition includes, for example, Ni: 0.4 to 4.8% by mass, Si: 0.1 to 1.2%, and Mg: 0.3% or less or Zn: 15% or less as required. Further, if necessary, the composition contains one or more of Sn, Co, Cr, P 2, B 3, Al, Fe 3, Zr 3, Ti 3, and Mn 3 in a total amount of 3% or less, and the remainder is substantially composed of Cu.

JP 2009-263784 A JP 2008-95186 A JP 2006-283059 A JP 2007-1000014 A

The conventional Cu-Ni-Si-based Corson alloy has a large variation in fatigue characteristics and is not sufficient to be used as a material for various electronic components in a predetermined shape for a long time in a high temperature and high vibration environment. In addition, the ease of processing to obtain a predetermined shape as well as bending workability was not sufficient.
This invention is made | formed in view of such a situation, and it aims at providing the Cu-Ni-Si type | system | group copper alloy which has the outstanding deep drawing workability and fatigue resistance.

As a result of intensive studies, the inventors of the present invention contain 1.0 to 3.0 mass% Ni, contain Si at a concentration of 1/6 to 1/4 with respect to the mass% concentration of Ni, and further Sn. 0.2-0.8 mass%, Zn 0.3-1.5 mass%, Mg 0.001-0.2 mass%, with the balance being Cu- In a Ni-Si based copper alloy plate, the Goss orientation density measured by the EBSD method with a scanning electron microscope with a backscattered electron diffraction image system is 2.0 to 6.0%, and the KAM (Kernel Average Missoration) The average value is 0.9 to 1.5 °, and the ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the crystal grain boundary is 60 to 70%. And exhibits excellent deep drawing workability and fatigue resistance Heading was.

  In addition, Goss orientation density and KAM (Kernel Average Misoration) measured by the EBSD method with a scanning electron microscope with a backscattered electron diffraction image system are greatly involved in fatigue resistance characteristics, and scanning with a backscattered electron diffraction image system. The ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the crystal grain boundary measured by the EBSD method using a scanning electron microscope greatly affects deep drawability. I found.

  In addition, the Cu-Ni-Si based copper alloy sheet of the present invention is manufactured in a process including hot rolling, cold rolling, solution treatment, aging treatment, pickling treatment, final cold rolling, and low temperature annealing in this order. In this case, the Goss orientation density and KAM (Kernel Average Misoration) measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system are basically determined by mechanical polishing and polishing in the pickling process in the manufacturing process. Depending on the conditions of chemical polishing, the total special grain boundary length Lσ of the special grain boundary relative to the total grain boundary length L of the grain boundary measured by the EBSD method with a scanning electron microscope with a backscattered electron diffraction image system It has also been found that the ratio (Lσ / L) is affected by the cold rolling processing rate and the final cold rolling processing rate immediately before the solution treatment in the manufacturing process.

From these findings, the Cu—Ni—Si based copper alloy sheet excellent in deep drawability and fatigue resistance of the present invention contains 1.0 to 3.0 mass% Ni, and the mass% concentration of Ni. 1 to 1 to 1/4 of the concentration of Si , 0.2 to 0.8 mass% of Sn, 0.3 to 1.5 mass% of Zn, and 0.001 to Mg. It contains 0.2% by mass, the balance is made of Cu and inevitable impurities, and the Goss orientation density measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system is 2.0 to 6.0%. Yes, the average value of KAM is 0.9 to 1.5 °, and the ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the crystal grain boundary is 60 to It is characterized by 70%.

Ni and Si form fine particles of an intermetallic compound mainly composed of Ni ₂ Si by performing an appropriate heat treatment. As a result, the strength of the alloy is significantly increased and at the same time the electrical conductivity is increased.
Ni is added in the range of 1.0 to 3.0% by mass, preferably 1.5 to 2.5% by mass. If Ni is less than 1.0% by mass, sufficient strength cannot be obtained. When Ni exceeds 3.0 mass%, a hot crack will generate | occur | produce. The addition concentration (mass%) of Si is 1/6 to 1/4 of the addition concentration (mass%) of Ni. If the Si addition concentration is less than 1/6 of the Ni addition concentration, the strength is reduced. If the Si addition concentration is more than 1/4 of the Ni addition concentration, not only does not contribute to the strength, but the conductivity is reduced due to excessive Si.
When the Goss orientation density is less than 2.0%, the fatigue resistance is lowered, and when the Goss orientation density is more than 6.0%, the fatigue resistance is lowered and the numerical value is increased and the tensile strength is also lowered. There is.
When the average value of KAM is less than 0.9 ° or exceeds 1.5 °, the fatigue resistance is deteriorated.
If the ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundaries is less than 60% or exceeds 70%, the deep drawability is deteriorated.

The S n and Zn, has the effect of improving the strength and heat resistance, further improvement effect of stress relaxation characteristics of Sn is, the Zn, an effect of improving the heat resistance of the solder joint. Sn is added in the range of 0.2 to 0.8 mass%, and Zn is added in the range of 0.3 to 1.5 mass%. If it is below the above range, the desired effect cannot be obtained, and if it exceeds, the conductivity is lowered.

Although the M g has the effect of improving the stress relaxation resistance and hot workability, castability and exceeds 0.2 wt% (casting surface quality deterioration), hot workability and plating thermal peeling resistance is lowered .

Furthermore, the Cu—Ni—Si based copper alloy of the present invention is further Fe: 0.007 to 0.25 mass%, P: 0.001 to 0.2 mass%, and C: 0.0001 to 0.001 mass. %, Cr and Zr : 0.001 to 0.3% by mass or one or more of them may be contained.
Fe has the effect of improving the hot rolling property (the effect of suppressing the occurrence of surface cracks and ear cracks) and the effect of minimizing the Ni and Si compound precipitation, thereby improving the plating heat adhesion. Although there is an action to increase the reliability, if the content is less than 0.007%, a desired effect cannot be obtained in the above action. On the other hand, if the content exceeds 0.25%, the hot rolling effect is saturated. However, since the decreasing tendency appears and the conductivity is adversely affected, the content is determined to be 0.007 to 0.25%.
P has an effect of suppressing a decrease in spring property caused by bending, thereby improving an insertion / extraction characteristic of a connector obtained by molding and an effect of improving migration resistance. If the content is less than 001%, the desired effect cannot be obtained. On the other hand, if the content exceeds 0.2%, the heat resistance peelability of the solder is remarkably impaired. %.
C has an effect of improving punching workability, and further has an effect of improving the strength of the alloy by refining a compound of Ni and Si. However, when the content is less than 0.0001%, the desired effect is obtained. On the other hand, if the content exceeds 0.001%, the hot workability is adversely affected. Therefore, the C content is set to 0.0001 to 0.001%.
Cr and Zr have a strong affinity for C and make it easy to contain C in the Cu alloy. In addition, Ni and Si compounds are further refined to improve the strength of the alloy and by precipitation of the alloy itself, the strength is further increased. Although it has an action to improve, even if the content of one or two of Cr and Zr is less than 0.001%, the effect of improving the strength of the alloy cannot be obtained, while it exceeds 0.3% If it is contained, a large precipitate of Cr and / or Zr is generated, which results in poor plating properties, poor punching workability, and further deteriorates hot workability. Therefore, the content of one or two of Cr and Zr is set to 0.001 to 0.3%.

Furthermore, the manufacturing method of the Cu-Ni-Si-based copper alloy plate excellent in deep drawing workability and fatigue resistance of the present invention includes hot rolling, cold rolling, solution treatment, aging treatment, pickling treatment, When manufacturing a copper alloy sheet in a process including final cold rolling and low temperature annealing in this order, the processing rate during cold rolling immediately before the solution treatment is performed at 50 to 60%, and polishing during pickling processing The mechanical polishing and chemical polishing are carried out at a final cold rolling rate of 3 to 20% , and the mechanical polishing is carried out with a polishing roll having a surface grain size of # 320 to # 600, The chemical polishing is performed by immersing in a treatment solution containing 5 to 20% by mass of sulfuric acid and 1 to 10% by mass of hydrogen peroxide at a solution temperature of 30 to 70 ° C. for 10 to 30 seconds .

The Goss orientation density measured by the EBSD method with a scanning electron microscope with a backscattered electron diffraction image system is obtained by performing chemical polishing followed by mechanical polishing under optimum conditions for polishing during pickling. 0 to 6.0% and an average value of KAM is set to 0.9 to 1.5 ° to exhibit excellent fatigue resistance. If either the Goss orientation density or the average value of KAM is outside the above specified range value, excellent fatigue resistance is not exhibited.
A scanning type with a backscattered electron diffraction image system is implemented by carrying out the processing rate at the time of cold rolling immediately before the solution treatment at 50 to 60% and the final cold rolling at a processing rate of 3 to 20%. The ratio of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the grain boundary measured by the EBSD method with an electron microscope (Lσ / L) is 60 to 70%, and excellent deep drawing To show the sex.
By making the processing rate at the time of cold rolling immediately before the solution treatment 50-60%, make a substrate with Lσ / L 60-70%, and the final cold rolling processing rate 3-20% Therefore, Lσ / L can be kept within the range of 60 to 70%.
If the processing rate at the time of cold rolling immediately before the solution treatment is less than 50% or more than 60%, the substrate preparation effect is not sufficient, and the processing rate of the final cold rolling is less than 3% or 20%. If it exceeds, Lσ / L does not fall within the range of 60 to 70%, and the deep drawability is deteriorated.

Mechanical polishing is performed by pressing with a polishing roll having a surface particle size (according to JIS R6001) of # 320 to # 600, followed by chemical polishing containing 5-20 mass% sulfuric acid and 1-10 mass% hydrogen peroxide. By performing immersion for 10 to 30 seconds in a treatment liquid having a liquid temperature of 30 to 70 ° C., the Goss orientation density measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system is 2.0 to 2.0. The average value of KAM falls within the range of 0.9 to 1.5 °, and excellent fatigue resistance is exhibited.
If the surface particle size of the polishing roll is less than # 320 or exceeds # 600, the Goss orientation density mainly does not fall within the predetermined range, and the temperature of the chemical polishing liquid or the immersion time in the chemical polishing liquid is outside the above range. When it is, there exists a tendency which the average value of KAM does not mainly fall in the predetermined range.

  The present invention relates to a Cu-Ni-Si based copper alloy having excellent deep drawing workability and fatigue resistance capable of withstanding use under high temperature and high vibration environment for a long time in a predetermined shape as a material of various electronic components. I will provide a.

  Hereinafter, embodiments of the present invention will be described.

[Component composition of copper alloy strip]
The copper alloy strip of the present invention is 1.0% by mass and contains 1.0 to 3.0% by mass of Ni, and contains Si at a concentration of 1/6 to 1/4 with respect to the mass% concentration of Ni. The balance is Cu and inevitable impurities.
Ni and Si form fine particles of an intermetallic compound mainly composed of Ni ₂ Si by performing an appropriate heat treatment. As a result, the strength of the alloy is significantly increased and at the same time the electrical conductivity is increased.
Ni is added in the range of 1.0 to 3.0% by mass, preferably 1.5 to 2.5% by mass. If Ni is less than 1.0% by mass, sufficient strength cannot be obtained. When Ni exceeds 3.0 mass%, a hot crack will generate | occur | produce. The addition concentration (mass%) of Si is 1/6 to 1/4 of the addition concentration (mass%) of Ni. If the Si addition concentration is less than 1/6 of the Ni addition concentration, the strength is reduced. If the Si addition concentration is more than 1/4 of the Ni addition concentration, not only does not contribute to the strength, but the conductivity is reduced due to excessive Si.
Moreover, this copper alloy may contain Sn 0.2-0.8 mass% and Zn 0.3-1.5 mass% further with respect to said basic composition.
Sn and Zn have an effect of improving strength and heat resistance, Sn has an effect of improving stress relaxation resistance, and Zn has an effect of improving heat resistance of solder joints. Sn is added in the range of 0.2 to 0.8 mass%, and Zn is added in the range of 0.3 to 1.5 mass%. If it is below the above range, the desired effect cannot be obtained, and if it exceeds, the conductivity is lowered.
Moreover, this copper alloy may contain 0.001-0.2 mass% of Mg further with respect to said basic composition. Mg has an effect of improving stress relaxation characteristics and hot workability, and is added in the range of 0.001 to 0.2 mass%. When it exceeds 0.2% by mass, castability (decrease in casting surface quality), hot workability, and plating heat resistance peelability are deteriorated.
Moreover, this copper alloy is further Fe: 0.007-0.25 mass%, P: 0.001-0.2 mass%, C: 0.0001-0.001 mass with respect to said basic composition. %, Cr: 0.001 to 0.3 mass%, Zr: 0.001 to 0.3 mass%, or one or more of them may be contained.
Fe has the effect of improving the hot rolling property (the effect of suppressing the occurrence of surface cracks and ear cracks) and the effect of minimizing the Ni and Si compound precipitation, thereby improving the plating heat adhesion. Although there is an action to increase the reliability, if the content is less than 0.007%, a desired effect cannot be obtained in the above action. On the other hand, if the content exceeds 0.25%, the hot rolling effect is saturated. However, since the decreasing tendency appears and the conductivity is adversely affected, the content is determined to be 0.007 to 0.25%.
P has an effect of suppressing a decrease in spring property caused by bending, thereby improving an insertion / extraction characteristic of a connector obtained by molding and an effect of improving migration resistance. If the content is less than 001%, the desired effect cannot be obtained. On the other hand, if the content exceeds 0.2%, the heat resistance peelability of the solder is remarkably impaired. %.
C has an effect of improving punching workability, and further has an effect of improving the strength of the alloy by refining a compound of Ni and Si. However, when the content is less than 0.0001%, the desired effect is obtained. On the other hand, if the content exceeds 0.001%, the hot workability is adversely affected. Therefore, the C content is set to 0.0001 to 0.001%.
Cr and Zr have a strong affinity for C and make it easy to contain C in the Cu alloy. In addition, Ni and Si compounds are further refined to improve the strength of the alloy and by precipitation of the alloy itself, the strength is further increased. Although it has an action to improve, even if the content of one or two of Cr and Zr is less than 0.001%, the effect of improving the strength of the alloy cannot be obtained, while it exceeds 0.3% If it is contained, a large precipitate of Cr and / or Zr is generated, which results in poor plating properties, poor punching workability, and further deteriorates hot workability. Therefore, the content of one or two of Cr and Zr is set to 0.001 to 0.3%.

[Alloy structure of copper alloy strip]
The Cu—Ni—Si based copper alloy strip of the present invention has a Goss orientation density of 2.0 to 6.0% measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system in the alloy structure. Yes, the average value of KAM is 0.9 to 1.5 °, and the ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the crystal grain boundary is 60 to It is 70% and is excellent in deep drawing workability and fatigue resistance.

[Goss orientation density, KAM, Lσ / L]
The measurement of Goss orientation density, KAM, and special grain boundary ratio by the EBSD method was performed as follows.
After mechanical polishing and buffing of a 10 mm x 10 mm sample, the surface was adjusted with an ion milling device manufactured by Hitachi High-Technologies Corporation with an acceleration voltage of 6 kV, an incident angle of 10 °, and an irradiation time of 15 minutes. S-3400N ") and an EBSD measurement / analysis system OIM (Orientation Imaging Micrograph) manufactured by TSL, the measurement area is divided into hexagonal areas (pixels), and each divided area is incident on the sample surface. The Kikuchi pattern was obtained from the reflected electrons of the electron beam and the orientation of the pixel was measured. The measured azimuth data was analyzed using the analysis software (software name “OIM Analysis”) of the system, and various parameters were calculated. The observation conditions were an acceleration voltage of 25 kV, a measurement area of 300 μm × 300 μm, and a distance (step size) between adjacent pixels of 0.5 μm. An orientation difference between adjacent pixels of 5 ° or more was regarded as a crystal grain boundary.
The Goss orientation density is calculated as the area ratio of the total area of pixels in the orientation with the orientation of {110} on the rolling surface and <001> parallel to the rolling direction and within 15 ° from the ideal orientation when expressed by the density mirror index. did.
When the Goss orientation density is less than 2.0%, the fatigue resistance is lowered. When the Goss orientation density is more than 6.0%, the fatigue resistance is lowered, the value varies, and the tensile strength tends to be lowered.
KAM calculated the average value of the azimuth | direction difference of a certain pixel in a crystal grain, and the adjacent pixel which exists in the range which does not exceed a crystal grain boundary, and computed it as the average value in all the pixels which comprise the measurement total area.
When the average value of KAM is less than 0.9 ° or exceeds 1.5 °, the fatigue resistance is deteriorated.
For the special grain boundary, the total grain boundary length L of the grain boundary in the measurement range is measured, and the grain boundary length ratio Lσ between the total special grain boundary length Lσ and the total grain boundary length L of the above measured grain boundary. / L was calculated as a special grain boundary length ratio.
If the ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundaries is less than 60% or exceeds 70%, the deep drawing workability deteriorates.

[Production method]
The method for producing a Cu—Ni—Si based copper alloy of the present invention is a process including hot rolling, cold rolling, solution treatment, aging treatment, pickling treatment, final cold rolling, and low temperature annealing in this order. When manufacturing a copper alloy sheet, the processing rate during cold rolling immediately before the solution treatment is 50 to 60%, mechanical polishing and chemical polishing are performed during polishing during pickling, and the final cold The rolling processing rate is 3 to 20%.
Goss orientation density measured by EBSD method using a scanning electron microscope with a backscattered electron diffraction image system by performing chemical polishing followed by mechanical polishing under optimum conditions for polishing during pickling treatment in the manufacturing process Of 2.0 to 6.0% and an average value of KAM of 0.9 to 1.5 °, exhibiting excellent fatigue resistance. If either the Goss orientation density or the average value of KAM is outside the specified range value, excellent fatigue resistance is not exhibited.
With backscattering electron diffraction image system, the processing rate during cold rolling immediately before the solution treatment in the manufacturing process is performed at 50 to 60%, and the final cold rolling is performed at a processing rate of 3 to 20%. The ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the crystal grain boundary measured by the EBSD method using a scanning electron microscope of 60 to 70% was excellent. Demonstrate deep drawability.
By making the processing rate at the time of cold rolling immediately before the solution treatment 50-60%, make a substrate with Lσ / L 60-70%, and the final cold rolling processing rate 3-20% Thus, Lσ / L is within the range of 60 to 70%.
If the processing rate at the time of cold rolling immediately before the solution treatment is less than 50% or more than 60%, the substrate preparation effect is not sufficient, and the processing rate of the final cold rolling is less than 3% or 20%. If it exceeds, Lσ / L does not fall within the range of 60 to 70%, and the deep drawability is deteriorated. The cold rolling may be performed a plurality of times with the annealing treatment or the like interposed therebetween, and the cold rolling immediately before the solution heat treatment may be a processing rate in the above range among the plurality of cold rollings.
Further, mechanical polishing is performed with a polishing roll having a surface particle size (based on JIS R6001) of # 320 to # 600, and chemical polishing is performed at a liquid temperature of 30 to 20% by mass sulfuric acid and 1 to 10% by mass hydrogen peroxide. The Goss azimuth density measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system is 2.0 to 6 by being immersed in a processing solution at ˜70 ° C. for 10 to 30 seconds. 0.0%, the average value of KAM falls within the range of 0.9 to 1.5 °, and excellent fatigue resistance is exhibited.
When the surface particle size of the polishing roll is less than # 320 or exceeds # 600, the Goss orientation density is not mainly within the predetermined range value, and the temperature of the chemical polishing liquid or the immersion time in the chemical polishing liquid is in the above range. If it is outside, there is a tendency that the average value of KAM does not mainly fall within the predetermined range value.

The following method is mention | raise | lifted as an example of a specific manufacturing method.
First, materials are prepared so as to have the composition of the Cu—Ni—Si based copper alloy plate of the present invention, and melt casting is performed using a low frequency melting furnace in a reducing atmosphere to obtain a copper alloy ingot. Next, after heating this copper alloy ingot to 900-980 degreeC, it is set as the hot-rolled board of moderate thickness by hot rolling, and after hot-cooling this hot-rolled board, both sides are faced moderately. Next, after performing cold rolling at a rolling rate of 60 to 90% and producing a cold-rolled sheet having an appropriate thickness, after performing continuous annealing at 710 to 750 ° C. for 7 to 15 seconds, Cold rolling is performed at a processing rate of 50 to 60% to produce a cold rolled sheet having an appropriate thickness, and the cold rolled sheet is held at 710 to 780 ° C. for 7 to 15 seconds and then rapidly cooled to perform a solution treatment. Apply.
Next, after holding at 430 to 470 ° C. for 3 hours and performing an aging treatment, mechanical polishing is carried out with polishing rolls having a surface particle size of # 320 to # 600 by polishing during pickling, and chemical polishing is performed. Is immersed in a treatment solution containing 5 to 20% by mass of sulfuric acid and 1 to 10% by mass of hydrogen peroxide for 10 to 30 seconds, and finally processed at a processing rate of 3 to 20%. After cold rolling, continuous low temperature annealing is performed at 300 to 400 ° C. for 20 to 60 seconds to produce a copper alloy sheet.
The Cu—Ni—Si-based copper alloy plate thus produced contains 1.0 to 3.0% by mass of Ni, and Si has a concentration of 1/6 to 1/4 with respect to the mass% concentration of Ni. The balance is made of Cu and inevitable impurities, and the Goss orientation density measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system is 2.0 to 6.0%, The average value is 0.9 to 1.5 °, and the ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L of the crystal grain boundary is 60 to 70%. Excellent deep drawability and fatigue resistance.

  Materials were prepared so as to have the components shown in Table 1, and cast after melting using a low-frequency melting furnace in a reducing atmosphere to produce a copper alloy ingot having a thickness of 80 mm, a width of 200 mm, and a length of 800 mm. . After heating this copper alloy ingot to 900-980 degreeC, it was set as the hot rolled sheet of thickness 11mm by hot rolling, and after hot-cooling this hot rolled sheet, both surfaces were faced 0.5mm. Next, after cold rolling was performed at a rolling rate of 87% to produce a cold-rolled sheet having a thickness of 1.3 mm, continuous annealing was performed at 710 to 750 ° C. for 7 to 15 seconds. Table 1 Cold rolling (cold rolling immediately before the solution treatment) was performed at a processing rate shown in FIG. The cold-rolled sheet was held at 710 to 780 ° C. for 7 to 15 seconds and then rapidly cooled to give a solution treatment, and then held at 430 to 470 ° C. for 3 hours to perform an aging treatment. Next, after the pickling treatment is performed under the conditions shown in Table 1, the final cold rolling is performed under the conditions shown in Table 1, and the continuous low temperature is maintained at 300 to 400 ° C. for 20 to 60 seconds. It annealed and produced the copper alloy thin plate of Examples 1-10 and Comparative Examples 1-9.

  Samples obtained from the copper alloy thin plates of Examples 1 to 10 and Comparative Examples 1 to 9 were analyzed for Goss orientation density, KAM, and grain boundary by an EBSD method using a scanning electron microscope with a backscattered electron diffraction image system. The ratio (Lσ / L) of the total special grain boundary length Lσ of the special grain boundary to the total grain boundary length L was measured. Furthermore, the deep drawability and fatigue resistance of each sample were measured.

The measurement of Goss orientation density, KAM, and special grain boundary ratio by the EBSD method was performed as follows.
After mechanical polishing and buffing of a 10 mm x 10 mm sample, the surface was adjusted with an ion milling device manufactured by Hitachi High-Technologies Corporation with an acceleration voltage of 6 kV, an incident angle of 10 °, and an irradiation time of 15 minutes. S-3400N ") and an EBSD measurement / analysis system OIM (Orientation Imaging Micrograph) manufactured by TSL, the measurement area is divided into hexagonal areas (pixels), and each divided area is incident on the sample surface. The Kikuchi pattern was obtained from the reflected electrons of the electron beam and the orientation of the pixel was measured. The measured azimuth data was analyzed using the analysis software (software name “OIM Analysis”) of the system, and various parameters were calculated. The observation conditions were an acceleration voltage of 25 kV, a measurement area of 300 μm × 300 μm, and a distance (step size) between adjacent pixels of 0.5 μm. An orientation difference between adjacent pixels of 5 ° or more was regarded as a crystal grain boundary.
The Goss orientation density is calculated as the area ratio of the total area of pixels in the orientation with the orientation of {110} on the rolling surface and <001> parallel to the rolling direction and within 15 ° from the ideal orientation when expressed by the density mirror index. did.
KAM calculated the average value of the azimuth | direction difference of a certain pixel in a crystal grain, and the adjacent pixel which exists in the range which does not exceed a crystal grain boundary, and computed it as the average value in all the pixels which comprise the measurement total area.
For the special grain boundary, the total grain boundary length L of the grain boundary in the measurement range is measured, and the grain boundary length ratio Lσ between the total special grain boundary length Lσ and the total grain boundary length L of the above measured grain boundary. / L was calculated as a special grain boundary length ratio.
Deep drawability was measured as follows.
Using a test machine manufactured by Eriksen Co., with a punch diameter of Φ10 mm and a lubricant of grease, a cup was prepared, the appearance was observed, a good one was put on the ear, or a crack was generated on the ear. did.
The fatigue resistance was measured as follows.
In accordance with JIS Z2273, a double-bending plane bending fatigue test was performed and collected. The test piece was a strip with a width of 10 mm, and the parallel direction of the rolling and the length direction of the test piece were matched. The test conditions were the thickness t (mm) of the test piece, the maximum bending stress σ _B (MPa) applied to the surface of the test piece, the piece amplitude δ (mm) given to the test piece, the Young's modulus E (GPa) of the alloy, and the fulcrum -A test piece was installed so that the distance l (mm) between stress acting points satisfied the relationship of l = √ (3 Etδ / (2σ _B )), and the maximum bending stress σ _B was set to 500 (MPa). The number of times N was measured when ruptured. The number of measurements was 4 times, the average value of N was determined, and the fatigue life of each specimen was taken.
These measurement results are shown in Table 2.

  From the results of Tables 1 and 2, the Cu-Ni-Si-based copper alloy of the present invention is excellent in that it can withstand use under high temperature and high vibration environment for a long time in a predetermined shape as a material of various electronic components. It can be seen that it has deep drawability and fatigue resistance.

  As mentioned above, although the manufacturing method of embodiment of this invention was demonstrated, this invention is not limited to this description, A various change can be added in the range which does not deviate from the meaning of this invention.

Claims (3)

1.0 to 3.0% by mass of Ni, Si containing 1/6 to 1/4 of the concentration by mass of Ni, and Sn of 0.2 to 0.8% by mass, Scanning electron microscope with 0.3 to 1.5% by mass of Zn, 0.001 to 0.2% by mass of Mg, the balance consisting of Cu and inevitable impurities, with backscattered electron diffraction image system The Goss orientation density measured by EBSD method is 2.0 to 6.0%, the average value of KAM is 0.9 to 1.5 °, and it is special with respect to the total grain boundary length L of the grain boundary. A Cu—Ni—Si-based copper alloy sheet excellent in deep drawing workability and fatigue resistance, wherein the ratio (Lσ / L) of the total special grain boundary length Lσ of grain boundaries is 60 to 70%. Furthermore, Fe: 0.007 to 0.25 mass%, P: 0.001 to 0.2 mass%, C: 0.0001 to 0.001 mass%, Cr and Zr : 0.001 to 0.3 mass% The Cu-Ni-Si-based copper alloy plate according to claim 1, comprising one or more of the following. It is a manufacturing method of the copper alloy plate of Claim 1, Comprising: In the process which includes hot rolling, cold rolling, solution treatment, aging treatment, pickling processing, final cold rolling, and low temperature annealing in this order When producing a copper alloy sheet, the processing rate during cold rolling immediately before the solution treatment is performed at 50 to 60%, mechanical polishing and chemical polishing are performed during polishing during the pickling process, and the final cold The processing rate during rolling is 3 to 20% , the mechanical polishing is performed with a polishing roll having a surface particle size of # 320 to # 600, and the chemical polishing is 5 to 20% by mass of sulfuric acid and hydrogen peroxide 1 Cu-Ni-Si system excellent in deep drawing workability and fatigue resistance, characterized by being immersed for 10 to 30 seconds in a treatment liquid containing 10 to 10% by mass of a liquid temperature of 30 to 70 ° C A method for producing a copper alloy sheet.